High RPMS at 55 MPH

Steve, at 55 with a 26" tire and a 5.56 gear you would be around 4000RPM.

Something isn't right. Speedo off, tach not right and I doubt you have 5.56's.

Could the converter be slipping that bad?

Is the trans shifting firmly into drive?

Do you have the correct toothed gear in the trans to match the rear gear?

What tach, aftermarket?

Does it sound like it's revving high or is this just what you are seeing?